ack can get blocked by files

[Sworddragon]

Initially this issue was reported here: https://bugs.launchpad.net/ubuntu/+source/ack-grep/+bug/1267948
It is still reproducible with ack 2.14 and I'm assuming that it just hit a file that waits for input. Maybe ack should check for such files and then skip them.

[petdance]

What does grep do in such a situation?

[Sworddragon]

Grep does wait too.

[petdance]

If grep has the same problem, then I don't know that ack will be able to do any better.

[Sworddragon]

If I'm not wrong telling the file position should always fail on such files without blocking. This could be used as a way to detect such files.

[Sworddragon]

Just a little notice: I have now also opened a ticket for this for grep on Launchpad: https://bugs.launchpad.net/ubuntu/+source/grep/+bug/1447216

[hoelzro]

Related: #214 #481

[xtaran]

I don't think this needs to be fixed at all because it is no bug but just how Linux works. Grepping through whole /proc just doesn't make sense as all files in there are special and only have some file-ish properties.

[Sworddragon]

/proc was just an example but such files can appear at any location (for example the text editor SciTE is storing such a file in /tmp if opened).

[petdance]

Thanks for the input. I'm closing this as acceptable.